Putman scale (or ancylus scale)

Systematic position: The insect belongs to the order Hemiptera and the family Diaspididae. These are armored scale insects, distinguished by the fact that they produce a protective cover (scale) over their bodies, made of wax and exuviae, which shields them from environmental stress and pesticides.

Host plants: This pest is polyphagous and infests a wide range of fruit and ornamental trees. Primary hosts include members of the Rosaceae family such as apple, pear, plum, and cherry trees. It is also commonly found on maples, lindens, and various deciduous forest species.

Biology and life cycle: The pest typically overwinters as second-instar nymphs on the bark of twigs and branches. In early spring, the nymphs mature into adults. Females lay eggs under their protective scales, where the nymphs eventually emerge. Depending on the geographical region, the life cycle may involve one or more generations per year.

Damage and economic impact: Feeding by sucking sap leads to severe debilitation of the host plant. The bark may become corky, cracked, and lose its elasticity. Heavy infestations lead to stunted growth, leaf chlorosis, premature senescence, and in extreme cases, the dieback of entire branches or the death of young trees.

• Application of horticultural oils during the dormant season to suffocate overwintering nymphs.
• Monitoring for crawler emergence to apply systemic or contact insecticides at the correct time.
• Pruning and destroying heavily infested branches to reduce local populations.
• Promoting natural predators, such as parasitic wasps and predatory lady beetles.
• Ensuring rigorous quarantine inspections of new nursery stock to prevent spread.